Kidney involvement in systemic sclerosis (SSc) is primarily manifested by scleroderma renal crisis (SRC). Formerly, it was the most severe complication in scleroderma and was the most frequent cause of death in these patients. More than 30years ago, with the development of angiotensin converting enzyme (ACE) inhibitors, SRC became a very treatable complication of scleroderma. Although there are still many patients who do not survive and have poor outcomes, early diagnosis of renal crisis and prompt therapeutic intervention can achieve excellent outcomes. Renal abnormalities independent of renal crisis have been noted, but can usually be attributed to other problems. Further understanding of the pathogenesis of renal disease in scleroderma may lead to additional improvement in the therapy of renal crisis and perhaps the disease in general. This chapter reviews the pathogenesis, clinical setting, and therapy of this serious complication of SSc.